Tag: new series

New Alex Moulton bicycle from BOA??

Rumours have begun circulating that a new model in the Moulton range is due to be announced.

Details are very sketchy at this point, but it seems that this new bicycle will be of spaceframe construction and with ETRTRO 369 /
17 inch wheels. It is to be built at the Moulton factory in Bradford on Avon.

All the signs are that this new model is designed to replace the AM. The AM is the classic spaceframe Moulton. In continuous production since 1982, the AM is a high-end high-performance bicycle and over the years it has benefited from technology trickle down from the New Series. For example, the flexitor in the rear pivot, the hydrolastic, and the adjustable wishbone stem are features that first appeared in the New Series, but were later introduced to the AM.

However, since the introduction of the TSR, many have questioned the AM's right to exist. The buyer with lots of money can spend a little more and get a New Series, or spend a little less and get a similar specification and weight with the TSR. Plus the AM hasn't really been pushed (at least outside of Japan) in recent years. The framesets have been available to dealers for custom building.

Furthermore, the geometry of the AM is a little outdated. It is the only spaceframe moulton in production without a unified rear triangle. It is also the only Moulton in production with the old style "knuckle shaped" bottom tube, which looked naff on the (separable) APBs and separable New Series', but look rather charming on the AM.

I would be very sorry to see the AM go out of production, especially before I can afford to purchase one! However, I can see the wisdom in updating and evolving the AM concept. I would welcome a straight bottom tube and unified rear triangle at a more affordable price.

Finally, it has been suggested that this new model will be priced below the TSR range. Now this is intriguing, especially as the new bicycle is to be produced at BOA. One has always paid a premium for a Bradford built bicycle. One wonders if they can produce a high quality bicycle in low numbers at a mass production price, but in low quantity. Seems unlikely!

As with many previous models, the new model may be unveiled at the annual Moulton Bicycle Club event at The Hall in Bradford on Avon in September.

Pogostick Continentals and Vibrating New Series

I'm using Continental Grand Prixs on my APB. These roll very nicely and are very light, but I've had my fair share of problems with them.

Firstly, one burst during my commute about 2 years ago. I wasn't going very fast, the inflation pressure was about perfect, I hadn't hit a pothole, and I wasn't carrying a load when the sidewall on the rear tyre blew out.

I was tempted to ditch them there and then, but I thought it was a once off and that it would be a mistake to write off any product, especially a tyre, based on one possibly freak occurrence so I bought a replacement and a spare.

Then late last year, when I put them on my Rigida Xplorer rims I got a pogo stick effect due the tyres not making a near perfect circle. It affected both front and back and made the bike unrideable.

I spent hours trying to get the bead to sit correctly on the rim, without success.

I partially solved the problem when I discovered that a medium width rim tape had been used when the wheels were built when a narrow tape would have been more appropriate.

The rim tape sat under the bead in places and not in others contributing to the inconsistent diameter of the inflated tyre.

What finally made the ride bearable again was the old trick of smearing washing up liquid on the inside of the rim wall, to reduce the friction between the bead and the rim. The bead is then encouraged to move more evenly outwards as the tyre is inflated.

Now the engineer in me did take into consideration that maybe the rims were at fault. I did previously have these tyres on standard Pashley wheels without a pogo problem.
However I also had Schwalbe City Jets on the Rigidas without a problem. It's difficult to say with certainty without an extensive experiment, but while the rims may be a contributing factor, they are unlikely to be the whole of the problem. I must conclude that the tyres are at least part, if not all of the problem.

What has this got to do with the New Series?

Well, on the moultonbicycle list on yahoogroups, there has been talk of a mystery vibration that occurs with Contis on the New Series, that kicks in at around 33km/h.

Well today, while the APB was on the work stand, I noticed the pogo effect again when I spun the wheels. And I noticed that the whole bike started to vibrate significantly at a certain speed. I used the bike computer to ascertain that this happened between approx 34 kph and 44kph. I repeated the the test several times with the same result. I also spun the wheels up to 70 kph, steadied the bike on the stand, and allowed them to slow down, thus ruling out that my hand pedalling motion was inducing any vibration.

the result was the same... Extensive vibration started at 44 kph and stopped around 33.

So are pogo stick contis a problem for others? Are they the reason for vibrating New Series phenomenon?

Anyhow, I have made a commitment to Contis for the time being having a pretty unworn pair on the APB, and a spare pair in the shed. So I'm pretty determined to make them work for me, instead of me working for them as seems to be the case at times!